A strong cold front will move through the area later in the day tomorrow, and ahead of it we will see a chance for strong to severe thunderstorms.
The atmosphere will have enough instability thanks to temperatures in the mid 70s and dew points in the low 60s tomorrow afternoon. Winds at the surface will be coming from the south and gusting as high as 20-25 mph throughout the day, which will help bring in the higher temperatures and moisture.
Thunderstorms will begin to form as early as the mid afternoon and continue to move through the area from west to east throughout the evening.
I think storms could initially move into areas west of the Illinois River as early as 3-4 PM, move through the Illinois River Valley between 6-8 PM, and then be pushing east of the I-55 corridor by 9-10 PM.
Initially, discrete individual cells may form, but as they move east they will likely congeal into a more linear structure.
High winds of 60 mph and 1" diameter hail will be the primary threats within any storms tomorrow evening. There will be enough low-level wind shear to introduce the chance for an isolated tornado or two, especially within any individual cells.
I would encourage you to stay weather aware between 3-10 PM tomorrow afternoon and evening, and make sure that you have ways to receive any severe weather warnings that are issued. A NOAA Weather Radio is the best way to receive warnings, and you can also download our Heart of Illinois ABC app which will send you severe weather alerts, as well as the ability to track storms using interactive radar.
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